Invasion History

First Non-native North American Tidal Record:
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Symplegma brakenhielmi is widely distributed and its native region is unknown. Confusion with S. viride (Herdmann 1886) has added to uncertainty over its range.  It is widespread and cryptogenic in the tropical Atlantic and Indo-West Pacific.  It is considered introduced in Hawaii, Guam, the eastern Mediterranean, and the Eastern Pacific, including tropical Mexico, Pacific Panama, and the Galapagos Islands (Lambert 2002; Carlton and Eldredge 2009; Shenkar and Loya 2009; Moreno-Davila 2010; Carmen et al. 2011; Lambert 2019). 

North American Invasion History:

Invasion History Elsewhere in the World:

In the Eastern Pacific, Symplegma brakenhielmi was found at the mouth of the lagoon of Corralero, Oaxaca, Mexico, in 2009 (Moreno-Davila 2010). In the Indo-West Pacific, it is considered introduced in harbors in Guam (Lambert 2002; Lambert 2003). In the Mediterranean, S. brakenhielmi was probably first collected by Peres in 1958 but was identified as S. viride by Peres (1958) and Millar (1975, both cited by Shenkar and Loya 2009). It has also been found in Turkey, Cyprus, and Libya (Cinar et al. 2005; Ulman et al. 2017; Rizgalla et al. 2019) and in the Mediterranean (Shenkar and Loya 2009). 


Symplegma brakenhielmi is an encrusting colonial tunicate, growing as a loosely packed mass of oval zooids, embedded in a transparent tunic. The siphons are short, and apertures are oval, located on the dorsal surface. The branchial structure consists of four longitudinal vessels, with two complete vessels, and two not reaching the branchial sac, and two reaching the dorsal laminae. There nine rows of stigmata. Testis vesicles are lobed. Zooids are 2.5 to 4 mm long, colors vary from gray to green, or orange red. Some colonies have red pigment outlining the pharyngeal band (Van Name 1945, as S. viride; Kott 1985; Rodrigues and da Rocha 1993; Lambert 2019).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Chordata
Subphylum:   Tunicata
Class:   Ascidiacea
Order:   Stolidobranchia
Family:   Styelidae
Genus:   Symplegma
Species:   brakenhielmi


Diandrocarpa brakenhielmi (Michaelsen, 1904)
Symplegma viride oceania (Van Name, 1945)
Symplegma oceania (Tokioka, 1961)
Symplegma viride brakenhielmi (Van Name, 1921)

Potentially Misidentified Species

Symplegma reptans
Native to the Indo-Pacific, introduced on the Pacific coast of Mexico and Californiia

Symplegma rubra
Cryptogenic in the Western Atlantic and Indo-Pacific, introduced in the Eastern Pacific

Symplegma viride
Probably native to the Western Atlantic, easily confused with S. brakenhielmi



Life History- A colonial (or compound) tunicate consists of many zooids, bearing most or all the organs of a solitary tunicate but modified to varying degrees for colonial life. Colonial tunicates of have small zooids, usually not organized in systems, and fully embedded in a mass of tunic material. Each zooid has an oral siphon and an atrial canal, opening to a shared cloacal chamber. Water is pumped into the oral siphon, through finely meshed ciliated gills on the pharynx, where phytoplankton and detritus are filtered and passed on mucus strings to the stomach and intestines. Excess waste is expelled in the outgoing atrial water (Van Name 1945; Barnes 1983).

Colonial tunicates reproduce both asexually, by budding, and sexually, from fertilized eggs developing into larvae. Buds can form from the body wall of the zooid. Colonies vary in size and can range from small clusters of zooids to huge spreading masses. The zooids are hermaphroditic, with eggs and sperm being produced by a single individual. Eggs may be self-fertilized or fertilized by sperm from nearby animals, but many species have a partial block to self-fertilization. Eggs are internally fertilized, and embryos are incubated in a brood pouch. Once they are mature, fertilized eggs hatch into a tadpole larva with a muscular tail, notochord, eyespots, and a set of adhesive papillae. The lecithotrophic (non-feeding, yolk-dependent) larva swims briefly before settlement. Swimming periods are usually less than a day, and some larvae can settle immediately after release, but the larval period can be longer at lower temperatures. Once settled, the tail is absorbed, the gill basket expands, and the tunicate begins to feed by filtering (Van Name 1945; Barnes 1983).

Symplegma brakenhielmi ranges widely in warm-temperate to tropical waters at marine salinities. As a colonial tunicate, it is a suspension feeder, filtering out phytoplankton and detritus.



Trophic Status:

Suspension Feeder



General HabitatMarinas & DocksNone

Life History

Tolerances and Life History Parameters

Maximum Temperature (ºC)28Field, Capitania, Brazil (Marins et al. 2010)
Minimum Salinity (‰)24Field, Capitania, Brazil (Marins et al. 2010)
Maximum Salinity (‰)32Field, Capitania, Brazil (Marins et al. 2010)
Broad Temperature RangeNoneWarm temperate-Tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Symplegma spp. are common fouling organisms on buoys, floats, pilings, and panels, but has not been reported to have significant economic impacts (Woods Hole Oceanographic Institution 1985). Symplegma spp. occurred on cultured mussels in Brazil but were not considered to have negative impacts on bivalve culture (Rocha 2009). 

Regional Impacts

NZ-IVNoneEcological ImpactCompetition

Overgrowing sponges and corals (Spyksma wt al. 2024)

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
SP-XII None 1998 Def Estab
SP-XXI None 1969 Def Estab
CIO-I None 0 Crypto Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 1885 Crypto Estab
SA-II None 1987 Crypto Estab
EA-II None 1964 Crypto Estab
AG-4 None 0 Crypto Estab
AG-5 None 0 Crypto Estab
CIO-II None 0 Crypto Estab
WA-IV None 0 Crypto Estab
NWP-2 None 1982 Crypto Estab
SP-IV None 0 Crypto Estab
NWP-3a None 0 Crypto Estab
AUS-XII None 0 Crypto Estab
AUS-XIII None 0 Crypto Estab
AUS-XIX None 0 Crypto Estab
AUS-XI None 0 Crypto Estab
AUS-VIII None 0 Crypto Estab
AUS-VII None 0 Crypto Estab
AUS-VI None 0 Crypto Estab
AUS-V None 0 Crypto Estab
AUS-IV None 0 Crypto Estab
AUS-III None 0 Crypto Estab
AUS-II None 0 Crypto Estab
EAS-I None 0 Crypto Estab
EAS-II None 0 Crypto Estab
SP-VII None 0 Crypto Estab
SP-XVIII None 0 Crypto Estab
CAR-IV None 1921 Crypto Estab
SP-XVI None 0 Crypto Estab
MED-V None 1958 Def Estab
EA-III None 1904 Crypto Estab
CAR-II None 1921 Crypto Estab
CAR-III None 0 Crypto Estab
SEP-H None 0 Def Estab
SA-IV None 0 Crypto Estab
SA-III None 0 Crypto Estab
G074 _CDA_G074 (Crystal-Pithlachascotee) 2003 Crypto Estab
G150 Mobile Bay 1885 Crypto Estab
G050 Charlotte Harbor 0 Crypto Estab
G030 North Ten Thousand Islands 1887 Crypto Estab
S200 Biscayne Bay 1921 Crypto Estab
S190 Indian River 2005 Crypto Estab
WA-V None 1952 Crypto Estab
NEP-VIII None 2009 Def Estab
PAN_PAC Panama Pacific Coast 0 Def Estab
PAN_CAR Panama Caribbean Coast 0 Crypto Estab
WA-I None 2016 Crypto Estab
SEP-Z None 2015 Def Estab
MED-IV None 2018 Def Estab
NZ-IV None 2015 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


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Carlton, James T.; Eldredge, Lucius (2009) Marine bioinvasions of Hawaii: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago., Bishop Museum Bulletin in Cultural and Environmental Studies 4: 1-202

Carman, Mary R. and 7 authors 2010 Ascidians at the Pacific and Atlantic entrances to the Panama Canal. <missing URL>

Carman, Mary, and 8 authors (2011) Ascidians at the Pacific and Atlantic entrances to the Panama Canal, Aquatic Invasions 6(4): 371-380

Çinar, M. E.; Noglu, M. Bilece; Özturk, B.; Katagan, T. ; Aysel, V. (2005) Alien species on the coasts of Turkey, Mediterranean Marine Science 6/2: 119-146

da Rocha, Rosa Morales and 13 authors (2010) Inventory of ascidians (Tunicata, Ascidiacea) from the National Park La Restinga, Isla Margarita, Venezuela, Biota Neotropica 10: published online

da Rocha, Rosana M.; Faria, Suzana B.; Moreno, Tatiane R. (2005) Ascidians from Bocas del Toro, Panama, Caribbean Journal of Science 41(3): 600-612

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Goodbody, Ivan; Webber, Mona (2003) The ascidian fauna of Port Royal, Jamaica I. Harbor and mangrove-dwelling species., Bulletin of Marine Science 73(2): 457-476

Granthom-Costa, Luciana Vieira; Werner Ferreira, Carlos Gustavo; Dias, Gustavo Muniz (2016) Biodiversity of ascidians in a heterogeneous bay from southeastern Brazil, Management of Biological Invasions 7: 5-12

Kott, P. (2005) Catalogue of Tunicata in Australian waters, Queensland Museum, Brisbane. Pp. 1-301

Kott, Patricia (1985) The Australian Ascidiacea Part 1, Phlebobranchia and Stolidobranchia., Memoirs of the Queensland Museum 23: 1-440

Lambert, Gretchen (2002) Nonindigenous ascidians in tropical waters., Pacific Science 56(3): 191-298

Lambert, Gretchen (2003) Marine biodiversity of Guam: the Ascidiacea., Micronesica 35-36: 584-593

Lambert, Gretchen (2019) Fouling ascidians (Chordata: Ascidiacea) of the Galápagos: Santa Cruz and Baltra Islands, Aquatic Invasions 14: 132-149

Locke, Andrea (2009) A screening procedure for potential tunicate invaders of Atlantic Canada., Aquatic Invasions 4(1): 71-79

Marins, Flavia O.; Novaes, Roberto L. M.; Rocha, Rosana M.; Junquiera, Andrea O. R. (2010) Non indigenous ascidians in port and natural environments in a tropical Brazilian bay, Zoologia 27(2): 213-222

Mead, A.; Carlton, J. T.; Griffiths, C. L. Rius, M. (2011b) Introduced and cryptogenic marine and estuarine species of South Africa, Journal of Natural History 39-40: 2463-2524

Monniot, C.; Monniot, F. (1985) [Littoral ascidians of Guadeloupe Island: IX. Characteristics of populations, ecology, relationships with the world fauna] (French), Tethys 11(3-4): 203-213

Monniot, C.; Monniot, F. (1997) Records of ascidians from Bahrain, Arabian Gulf with three new species., Journal of Natural History 31: 1623-1643

Monniot, Claude; Monniot, Francoise (1987) [The Ascidians of French Polynesia] (French), Memoires da Museum d'Histoire Naturelle 136: 106-119

Monniot, Claude; Monniot, Francoise; Griffiths, Charles; Schleyer, Michael (2001) South African Ascidians., Annals of the South African Museum 108(1): 1-141

Monniot, Claude; Monniot, Francoise; Laboutte, Pierre (1985) [Ascidians of the port of Papeete (French Polynesia); Relation to the environment and to intercontinental transport by navigation] (French), Bulletin du Museum National d'Histoire Naturelle. 4e Serie. Section A. Zoologie, Biologie et Ecologie Animales 7(3): 481-495

Monniot, Françoise (2018) Ascidians collected during the Madibenthos expedition in Martinique: 2. Stolidobranchia, Styelidae, Zootaxa 2: 291-318

Moreno-Davila, Betzabe Berenice (2010) <missing title>, Universidad del Mar, campus Puerto Angel, Oaxaca, Puerto Angel, Oaxaca, Mexico. Pp. 116

Nowosad, Damon M.; Taylor, Eric B. T (2013) Habitat variation and invasive species as factors influencing the distribution of native fishes in the lower Fraser River Valley, British Columbia, with an emphasis on brassy minnow (Hybognathus hankinso, Canadian Journal of Fisheries and Aquatic Sciences 91: 71-81

Paulay, Gustav; Kirkendale, Lisa; Lambert, Gretchen; Meyer, Chris (2002) Anthropogenic biotic interchange in a coral reef ecosystem: a case study from Guam, Pacific Science 56(2): 403-422

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Renganathan, T. K. (1985) On the occurrence of a colonial ascidian, Symplegma brakenhielmi from Tuticorin Coast of India with a brief description of its larva, Geobios New Reports 4: 75-77

Rho, Boon Jo; Park, Kyung-Sook (1998) Taxonomy of ascidians from Geojedo Island in Korea, Korean Journal of Systematic Zoology 14(3): 173-192

Rizgalla, Jamila; Ashinn, Andrew P.; Crocetta, Fabio (2021) New records of alien and cryptogenic marine bryozoan, mollusc, and tunicate species in Libya, BioInvasions Records 8: 590-597

Rodrigues, S. A.; da Rocha, R. M. (1993) Littoral compound Ascidians (Tunicata) from Sao Sebastiao, Estado de Sao Paulo, Brazil., Proceedings of the Biological Society of Washington 106: 728-739

Shenkar, Noa; Loya, Yossi (2009) Non-indigenous ascidians (Chordata: Tunicata) along the Mediterranean coast of Israel, Marine Biodiversity Records 2: 1-7

Swami, B. S.; Chapgar, B. F. (2002) Settlement pattern of ascidians in harbor waters of Mumbai, West Coast of India., Indian Journal of Marine Science 31(3): 207-212

Tamilselvi, M. ; Sivakumar, V.; Ali, H. Abdul Jaffar; Thilaga, R. D. (2011) Distribution of alien tunicates (ascidians) in Tuticorin coast, India, World Journal of Zoology 6(2): 164-172

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database.

Van Name, Willard G. (1921) Ascidians of the West Indian region and southeastern United States., Bulletin of the American Museum of Natural History 44: 283-494

Van Name, Willard G. (1945) The North and South American ascidians, Bulletin of the American Museum of Natural History 84: 1-462

Venugopalan, V. P.; Wagh, A. (1990) Biofouling of an offshore oil platform: Faunal composition and biomass, Indian Journal of Marine Science 19: 53-56

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Zambrano, René; Ramos, John (2021) Alien crustacean species recorded in Ecuador, Nauplius 29: e2021043